I have a dataframe with strings such as:
id <- c(1,2)
x <- c("...14.....5.......................395.00.........................14.........1..",
"......114.99....................124.99................")
df <- data.frame(id,x)
df$x <- as.character(df$x)
How can I extract only values with a decimal point in between such as 395.00, 114.99 and 124.99 and not 14, 5, or 1 for each row, and put them in a new column separated by a comma?
The ideal result would be:
id x2
1 395.00
2 114.99,124.99
The amount of periods separating the values are random.
library(stringr)
df$x2 = str_extract_all(df$x, "[0-9]+\\.[0-9]+")
df[c(1, 3)]
# id x2
# 1 1 395.00
# 2 2 114.99, 124.99
Explanation: [0-9]+ matches one or more numbers, \\. matches a single decimal point. str_extract_all extracts all matches.
The new column is a list column, not a string with an inserted comma. This allows you access to the individual elements, if needed:
df$x2[2]
# [[1]]
# [1] "114.99" "124.99"
If you prefer a character vector as the column, do this:
df$x3 = sapply(str_extract_all(df$x, "[0-9]+\\.[0-9]+"), paste, collapse = ",")
df$x3[2]
#[1] "114.99,124.99"
Related
['ax', 'byc', 'crm', 'dop']
This is a character string, and I want a count of all substrings, ie 4 here as output. Want to do this for the entire column containing such strings.
We may use str_count
library(stringr)
str_count(str1, "\\w+")
[1] 4
Or may also extract the alpha numeric characters into a list and get the lengths
lengths(str_extract_all(str1, "[[:alnum:]]+"))
If it is a data.frame column, extract the column as a vector and apply str_count
str_count(df1$str1, "\\w+")
data
str1 <- "['ax', 'byc', 'crm', 'dop']"
df1 <- data.frame(str1)
Here are a few base R approaches. We use the 2 row input defined reproducibly in the Note at the end. No packages are used.
lengths(strsplit(DF$b, ","))
## [1] 4 4
nchar(gsub("[^,]", "", DF$b)) + 1
## [1] 4 4
count.fields(textConnection(DF$b), ",")
## [1] 4 4
Note
DF <- data.frame(a = 1:2, b = "['ax', 'byc', 'crm', 'dop']")
I have a column with numerical comma-separated strings, e.g., '0,1,17,200,6,0,1'.
I want to create new columns for the sums of those numbers (or substrings) in the strings that are not equal to 0.
I can use something like this to count the sum of non-zero numbers for the whole string:
df$F1 <- sapply(strsplit(df1$a, ","), function(x) length(which(x>0)))
[1] 5
This outputs '5' as the number of substrings in for the example string above, which is correct as the number of substrings in '0,1,17,200,6,0,1' is indeed 5.
The challenge, however, is to be able to restrict the number of substrings. For example, how can I get the the count for only the first 3 or 6 substrings in the string?
You can use gsub and backreference to cut the string to the desired length before you count how many substrings are > 0:
DATA:
df1 <- data.frame(a = "0,1,17,200,6,0,1")
df1$a <- as.character(df1$a)
SOLUTION:
First cut the string to whatever number of substrings you want--here, I'm cutting it to three numeric characters (the first two of which are followed by a comma)--and store the result in a new vector:
df1$a_3 <- gsub("^(\\d+,\\d+,\\d+)(.*)", "\\1", df1$a)
df1$a_3
[1] "0,1,17"
Now insert the new vector into your sapply statement to count how many substrings are greater than 0:
sapply(strsplit(df1$a_3, ","), function(x) length(which(x>0)))
[1] 2
To vary the number of substrings, vary the number of repetitions of \\d+ in the pattern accordingly. For example, this works for 6 substrings:
df1$a_6 <- gsub("^(\\d+,\\d+,\\d+,\\d+,\\d+,\\d+)(.*)", "\\1", df1$a)
sapply(strsplit(df1$a_6, ","), function(x) length(which(x>0)))
[1] 4
EDIT TO ACCOUNT FOR NEW SET OF QUESTIONS:
To compute the maximum value of substrings > 0, exemplified here for df1$a, the string as a whole (for the restricted strings, just use the relevant vector accordingly, e.g., df1$a_3, df1$a_6 etc.):
First split the string using strsplit, then unlist the resulting list using unlist, and finally convert the resulting vector from character to numeric, storing the result in a vector, e.g., string_a:
string_a <- as.numeric(unlist(strsplit(df1$a, ",")))
string_a
[1] 0 1 17 200 6 0 1
On that vector you can perform all sorts of functions, including max for the maximum value, and sum for the sum of the values:
max(string_a)
[1] 200
sum(string_a)
[1] 225
Re the number of values that are equal to 0, adjust your sapply statement by setting x == 0:
sapply(strsplit(df1$a, ","), function(x) length(which(x == 0)))
[1] 2
Hope this helps!
I have character vector of the following form (this is just a sample):
R1Ng(10)
test(0)
n.Ex1T(34)
where as can be seen above, the first part is always some combination of alphanumeric and punctuation marks, then there are parentheses with a number inside. I want to create a numeric vector which will store the values inside the parentheses, and each number should have name attribute, and the name attribute should be the string before the number. So, for example, I want to store 10, 0, 34, inside a numeric vector and their name attributes should be, R1Ng, test, n.Ex1T, respectively.
I can always do something like this to get the numbers and create a numeric vector:
counts <- regmatches(data, gregexpr("[[:digit:]]+", data))
as.numeric(unlist(counts))
But, how can I extract the first string part, and store it as the name attribute of that numberic array?
How about this:
x <- c("R1Ng(10)", "test(0)", "n.Ex1T(34)")
data.frame(Name = gsub( "\\(.*", "", x),
Count = as.numeric(gsub(".*?\\((.*?)\\).*", "\\1", x)))
# Name Count
# 1 R1Ng 10
# 2 test 0
# 3 n.Ex1T 34
Or alternatively as a vector
setNames(as.numeric(gsub(".*?\\((.*?)\\).*", "\\1", x)),
gsub( "\\(.*", "", x ))
# R1Ng test n.Ex1T
# 10 0 34
Here is another variation using the same expression and capturing parentheses:
temp <- c("R1Ng(10)", "test(0)", "n.Ex1T(34)")
data.frame(Name=gsub("^(.*)\\((\\d+)\\)$", "\\1", temp),
count=gsub("^(.*)\\((\\d+)\\)$", "\\2", temp))
We can use str_extract_all
library(stringr)
lst <- str_extract_all(x, "[^()]+")
Or with strsplit from base R
lst <- strsplit(x, "[()]")
If we need to store as a named vector
sapply(lst, function(x) setNames(as.numeric(x[2]), x[1]))
# R1Ng test n.Ex1T
# 10 0 34
data
x <- c("R1Ng(10)", "test(0)", "n.Ex1T(34)")
I have a data.frame in which one of the columns is a list of numbers, separated by commas, with a variable length. Here is a simple example:
df <- data.frame(ids=c('1','2','3'), coords=c('1,2,3', '4,4,4,4', '9,8,7,6,5'))
ids coords
1 1,2,3
2 4,4,4,4
3 9,8,7,6,5
I want to create a new columns that is a list of numbers that are a function of the numbers in the coords column. For instance, the function x+10:
ids coords coordsf
1 1,2,3 11,12,13
2 4,4,4,4 14,14,14,14
3 9,8,7,6,5 19,18,17,16,15
We can use gsub
df$coordsf <- sub(',','',gsub('^|,', ',1',df$coords))
df$coordsf
#[1] "11,12,13" "14,14,14,14" "19,18,17,16,15"
Or
gsub("(,|^)(?=\\d)", "\\11", df$coords, perl=TRUE)
#[1] "11,12,13" "14,14,14,14" "19,18,17,16,15"
Or if we need to add 10
sapply(strsplit(as.character(df$coords), ","),
function(x) paste(as.numeric(x)+10,collapse=",") )
#[1] "11,12,13" "14,14,14,14" "19,18,17,16,15"
I have the following string:
str1<-"{a{c}{b{{e}{d}}}}"
In addition, I have a list of integers:
str_d <- ( 1, 2, 2, 4, 4)
There is one to one relation between the list to the string.
It means:
a 1
c 2
b 2
e 4
d 4
I would like to sort in alphabetic order only the characters of str1 that have same level.
It means to sort c, b (which have the same value 2) will yield b,c
and to sort e, d (which have the same value 4) will yield d,e.
The required result will be:
str2<-"{a{b}{c{{d}{e}}}}"
In addition a,b,c,d and e can be not only characters, but might be words, such as:
str1<-"{NSP{ARD}{BOS{{DUD}{COR}}}}"
How can I do it with keeping the { in their place?
brkts <- gsub("\\w+", "%s", str1)
strings <- regmatches(str1,gregexpr("[^{}]+",str1))[[1]]
fixed <- ave(strings, str_d, FUN=function(x) sort(x))
do.call(sprintf, as.list(c(brkts, fixed)))
[1] "{a{b}{c{{d}{e}}}}"
and
[1] "{NSP{ARD}{BOS{{COR}{DUD}}}}"
It will work for the first and second case. We first isolate the text with gsub and place %s instead. That will be used later for sprintf. Next we isolate the strings by splitting with strsplit on the comma that we placed after each group of bracket symbols. We then sort based on the sorting vector given and save the characters in the vector fixed. Lastly, we call sprintf on the brkts variable that we created at the beginning and the sorted strings.
Data
str_d <- c(1, 2, 2, 4, 4)
str1<-"{a{c}{b{{e}{d}}}}"
str1<-"{NSP{ARD}{BOS{{DUD}{COR}}}}"
One possible solution (using stringr package):
words <- str_extract_all(str1, '\\w+')[[1]]
ordered <- words[order(paste(str_d, words))]
formatter <- str_replace_all(str1, '\\w+', '%s')
do.call(sprintf, as.list(c(formatter, ordered)))
words is an extract of the words between the braces. I ordered those by sorting the combination of the words with str_d. E.g. the words will become:
1 a
2 c
2 b
4 e
4 d
Then I slap it all back together with sprintf().